Low performance rate between ssh nodes

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Hi, I have a wired problem with ssh and no idea how to analyze the problem.
So every hint is appreciated inlcuding the hint to another newsgroup.

Here the configuration of the 4 computers which I used
pc83 (OpenSSH_3.8.1p1 Debian-8.sarge.6, OpenSSL 0.9.7e 25 Oct 2004) a PC
which could only have an outgoing ssh connection, so I initialized
a tunnel from there to one of the next 2 notebooks. The connection is via

tine an older notebook Intel Celeron 184 Mhz
OpenSSH_3.8.1p1 Debian-8.sarge.6, OpenSSL 0.9.7e 25 Oct 2004
inside local network.

onnie a newer notebook Intel Celeron 547 MHz
OpenSSH_4.3p2 Debian-9, OpenSSL 0.9.8c 05 Sep 2006
inside local network.

pondus a workstation in my local network
OpenSSH_3.8.1p1 Debian-8.sarge.6, OpenSSL 0.9.7e 25 Oct 2004

The connection between all runs over an DSL-Internet-Router.

Now I copy an mp3-file to measure the network rate.
Here the result (Please don't be amazed about the localhost, it is a
scp-connection through an ssh-tunnel for technical reasons).

Copy the file from pc83 to onnie (Very SLOW!)
niels@onnie:~$ scp -P50022 localhost:dlf/DLF_FuT_30-10-2007.mp3 .
DLF_FuT_30-10-2007.mp3   100%   10MB  18.0KB/s   09:56

Copy the file from pc83 to tine (Acceptable Rate 6 times faster)
niels@tine:~$ scp -P50022 localhost:dlf/DLF_FuT_30-10-2007.mp3 .
DLF_FuT_30-10-2007.mp3   100%   10MB 124.4KB/s   01:26

To I thought there must be a network configuration or hardware problem at
onnie. But than I measured the rate between onnie/tine and my workstation
pondus. Here the result:
niels@pondus:/tmp$ scp onnie:dlf/DLF_FuT_29-10-2007.mp3 .
DLF_FuT_29-10-2007.mp3   100%   11MB 987.2KB/s   00:11
niels@pondus:/tmp$ scp tine:dlf/DLF_FuT_29-10-2007.mp3 .
DLF_FuT_29-10-2007.mp3   100%   11MB 434.4KB/s   00:25

So this time is tine a little bit slower, perhaps here is the slower cpu the
reason. Anyway the network configuration or hardware could not be the

So are the different SSH-version the reason? Or what else could it be?

Thanks for reading this long description. Last hint: all measurement was
made more than onetime and the result was allways the same.

Re: Low performance rate between ssh nodes

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Have you got measurements not involving ssh for comparison?

Is compression turned on?    Applying compression multiple times
to am mp3 file is likely to be an unrewarding experience.

Elvis Notargiacomo  master AT barefaced DOT cheek
http://www.notatla.org.uk/goen /

Re: Low performance rate between ssh nodes

Hi thanks for the answer:
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Well I turned compression off and indeed the performance increase, but at
onnie it was still bad.
I made than another test. I copied the file to an public server in the same
net where pc83 stands. I get than the same problem. So it seems that it has
nothing to do with ssh.
The interesting point is that the problem occurs only for connection to my
company. If I try to download via wget the kernel source everything is
fine. BTW No firewall is installed on both notebooks. So it looks that this
is a wired network problem - so I'm in the wrong newsgroup.

Thank for the help and have a nice time.


Re: Low performance rate between ssh nodes

Niels Stargardt schrieb:
Quoted text here. Click to load it

despite the reason of your problem:
instead of tunneling ssh over ssh, its faster to use nc (netcat) as
forwarding tunnel.

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